Re: [Amel Yacht Owners] Re: Prop Shaft Electrolysis
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I posted a schematic of the isolated ground for the engine in the files section, Jamie.
On Dec 3, 2015, at 6:15 PM, James Wendell ms42phantom54@... [amelyachtowners] <amelyachtowners@...> wrote:
Well, actually I do understand the concept of isolated ground, but I was not aware that Amel would go to the trouble of installing relays to break the DC wiring to the engine when it is shut down. There is no mention of that in any of my Amel schematics, but since I am new to this boat I still have things to learn.
And by the way, I hope I did not promote US standards as if they should be the world standard. I wish the US were on the metric system, for example, but please don't let me rant on about that one. I also wish we used single phase 230 volts like most of the rest of the world (at least Europe). There are many regs in the US that I disagree with, but electrical safety is a fairly strong one. I can see the benefit of an isolated ground from the perspective of galvanic corrosion control, but I still question the overall safety of such systems, particularly when it comes to AC earth connections.
Anyway, I have not yet selected the engine brand I will install. The easiest solution (but least desirable based on my recent disaster) would be a replacement Volvo Penta D3-110, third generation of course. That would maintain the existing systems as they are, including the isolated ground. Any other brand would have to be carefully evaluated to ensure total compatibility and to maintain the Amel way of life.
I will go check on that isolated ground everyone is talking about. Very interesting indeed.
s/v Phantom Amel 54
On Thursday, December 3, 2015 2:56 PM, "'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]" <amelyachtowners@...> wrote:
Isolated ground is probably not something that you learned in electrical engineering school, but it is an important thing to understand in a marine environment. Amel uses an isolated ground system where the DC negative IS NOT part of the engine frame. You will notice this with the temperature sensor and other sensors. Most marine engines have a single wire going to the temperature sensor because the engine is ground. Your Amel has an isolated ground and there will be two wires. The only time the DC negative is connected to the starter is when the start switch is turned to start.
Your alternators will also be isolated ground alternators. I know a Bavaria owner who failed to install the correctly grounded alternator and his entire saildrive became a sacrificial chunk of metal.
As to what ABYC thinks is important, I am not so sure. Just because they are American, does not mean they are right. I would argue a number of their publications, but that is for another day and another subject.
Good luck with your new engine...did you state what engine you plan to use?
On Thu, Dec 3, 2015 at 7:35 PM, James Wendell ms42phantom54@... [amelyachtowners] <amelyachtowners@...> wrote: